astronomy

Jacques Gauthier

Jacques Gauthier is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Jacques Gauthier rather than just read about it. In short: Jacques Armand Gauthier (born June 7, 1948, in New York City) is an American vertebrate paleontologist, comparative morphologist, and systematist, and one of the founders of the use of cladistics in biology. Life and career Gauthier is the son of Edward Paul Gauthier and Patricia Marie Grogan.

Key takeaways

Jacques Gauthier belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Jacques Gauthier to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Jacques Gauthier from memory before moving on to harder problems.

Reference excerpt

Jacques Armand Gauthier (born June 7, 1948, in New York City) is an American vertebrate paleontologist, comparative morphologist, and systematist, and one of the founders of the use of cladistics in biology.

Life and career Gauthier is the son of Edward Paul Gauthier and Patricia Marie Grogan. He received a B.S. degree in zoology at San Diego State University in 1973, a master's in biological science at the same institute in 1980, and a PhD in paleontology from the University of California, Berkeley, in 1984. Currently he is a professor of geology and geophysics and ecology and evolutionary biology and curator of vertebrate paleontology and vertebrate zoology at Yale University. His master's thesis, the content of which was published in 1982, is a classic work on the paleontology and phylogeny of the lizard clade Anguimorpha that remains a core reference for morphological research on Xenosauridae and Anguidae in particular. His PhD thesis constituted the first major cladistic analysis of Diapsida, as well as arguing for the monophyly of the dinosaurs. He followed this with an important paper on the origin of birds from theropods. This was the first detailed cladistic analysis of the theropod dinosaurs, and initiated a revolution in dinosaur phylogenetics, in which cladistics replaced the Linnaean system in the classification and phylogenetic understanding of the dinosaurs. Gauthier's corpus contributed the foundational phylogenetic studies of Archosauria and Lepidosauria, two major amniote clades; and he was the primary author of the foundational and still widely cited phylogenetic study of Amniota as a whole. The phylogenetic character sets from his 1984 and 1986 works, the 1988 amniote paper, and the 1988 lepidosaur and squamate papers still form the core of essentially all gross-anatomy-based phylogenetic analyses of these groups, and as such are among the most highly cited papers in amniote morphology and paleobiology. The 1988 amniote paper is also frequently cited to demonstrate the importance of taxon sampling in phylogenetic analysis, in particular the importance of sampling rare or fossil taxa that can break 'long branches' along which convergence can occur. Gauthier has argued together with Kevin de Queiroz for replacing Linnaean taxonomy with the PhyloCode. In addition to his theoretical work on systematics and taxonomy, Gauthier continues to study the anatomy and relationships of diapsids, particularly lepidosaurs. His lizard work currently focuses on Scincomorpha, following on a career-long interest in the unusual clade Xantusiidae. He is a principal investigator on the National Science Foundation-funded effort to reconstruct the phylogeny of lizards and snakes (Squamata) using gross anatomy and molecular structure, building on his earlier work in collaboration with Richard Estes and Kevin de Queiroz, which established the most widely accepted phylogeny of the group.

Footnotes

References Estes, R.; de Queiroz, K. & Gauthier, Jacques (1988): Phylogenetic relationships within Squamata. In: Estes, R. & Pregill, G. (eds.): The Phylogenetic Relationships of the Lizard Families: 15–98. Stanford University Press, Palo Alto. Gauthier, Jacques A. (1982): Fossil xenosaurid and anguid lizards from the early Eocene of Wyoming, and a revision of the Anguioidea. Contributions to Geology, University of Wyoming 21: 7–54. Gauthier, Jacques A. (1984): A cladistic analysis of the higher systematic categories of the Diapsida. [PhD dissertation]. Available from University Microfilms International, Ann Arbor, #85-12825, vii + 564 pp. Gauthier, J. A. (1986), "Saurischian monophyly and the origin of birds", in Padian, K. (ed.), The Origin of Birds and the Evolution of Flight, Memoirs of the California Academy of Sciences, vol. 8, Memoirs of the California Academy of Sciences, pp. 1–55, ISBN 0-940228-14-9 Gauthier, Jacques A.; Estes, R. & de Queiroz, Kevin (1988): A phylogenetic analysis of Lepidosauromorpha. In: Estes, R. & Pregill, G. (eds.): The Phylogenetic Relationships of the Lizard Families: 15–98. Stanford University Press, Palo Alto. Gauthier, J. A.; Kluge, A. G.; Rowe, T. (June 1988). "Amniote phylogeny and the importance of fossils" (PDF). Cladistics. 4 (2). John Wiley & Sons: 105–209. doi:10.1111/j.1096-0031.1988.tb00514.x. hdl:2027.42/73857. PMID 34949076. S2CID 83502693. Rowe, T. & Gauthier, Jacques (1990): Ceratosauria. In: Weishample, D.; Dodson, P. & Osmólska, Halszka (eds.): The Dinosauria: 151–168. University of California Press, Berkeley. de Queiroz, Kevin & Gauthier, Jacques A. (1992): Phylogenetic taxonomy. Annu. Rev. Ecol. Syst. 23: 449–480. Gauthier, Jacques A. (1994): The diversification of the amniotes. In: Prothero, D. (ed.): Major Features of Vertebrate Evolution: Short Courses in Paleontology: 129–159. Paleontological Society. Donoghue, M. J.; Gauthier, Jacques A. (June 2004). "Implementing the PhyloCode" (PDF). Trends Ecol. Evol. 19 (6): 281–282. Bibcode:2004TEcoE..19..281D. doi:10.1016/j.tree.2004.04.004. PMID 16701272. Archived from the original on 2011-04-01. Retrieved 2010-09-26.

External links Yale Peabody Museum

Worked examples

Example 1 — a first encounter with Jacques Gauthier

Start with the simplest possible case. Write down what Jacques Gauthier claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Jacques Gauthier before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Jacques Gauthier ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Jacques Gauthier

In research: Jacques Gauthier appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Jacques Gauthier in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Jacques Gauthier is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1948 births, American curators, American paleontologists, so understanding it makes those chapters shorter.
In everyday life: Look for Jacques Gauthier outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Jacques Gauthier in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Jacques Gauthier means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
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Frequently asked questions

What is Jacques Gauthier in simple terms?

Why does Jacques Gauthier matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Jacques Gauthier?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Jacques Gauthier.